1. Field of the Invention
The present invention relates to an information sharing system and information sharing method capable of securely executing access to an external service on a network.
2. Description of the Related Art
Conventionally, there has been developed an electronic blackboard device (hereinafter, referred to as an “interactive whiteboard (IWB)”) that displays information written thereon as image data (see Japanese Patent Application Laid-open No. 2013-39701). The IWB is configured as a so-called touch panel of which the front writing surface is composed of an integrated combination of a display device and a pointing device and is configured to output a signal according to the touch position.
The IWB acquires, for example, information written on the writing surface thereof by a user with a dedicated pen as image data by means of a touch panel function, and displays the image data on the display device composing the writing surface. Furthermore, the IWB can store the acquired image data in a memory or output the acquired image data to the outside through a communication interface. Moreover, the IWB can capture image data supplied from the outside through the communication interface and display the image data on the display device composing the writing surface.
Furthermore, recently, there has also been developed a technology to give a presentation or the like by using a large-sized tablet computer with a large display (touch panel). Especially, in the case of using a tablet computer with an extremely-large touch panel of, for example, 80 inches in diagonal size, the tablet computer can achieve the same functions as the above-described IWB. Hereinafter, such an IWB and a tablet computer used for the same purpose as the IWB are collectively referred to as “IWB”.
Meanwhile, a storage service that a server on the Internet provides a data storage area to a user has become common in recent years. When a user uses this storage service, the user registers user identifying information on the server in advance and transmits the user identifying information to the server when accessing the storage service to store data in the storage service or retrieve data from the storage service. As the user identifying information, a combination of a user name and a password is often used. The server performs authentication of the user identifying information transmitted from the user, and, when having authenticated the user, allows the user to access the storage service.
By using this storage service, the user can freely use his/her data without carrying the data as long as the user is in a given Internet connection environment. For example, even when the user borrows someone's computer at the place where the user went out, as long as the computer can be connected to the Internet, the user can access the storage service and perform download, update, or storage of his/her data.
Here, let's think of using a storage service through the above-described IWB. Also in this case, when accessing the storage service through the IWB, a user needs to be authenticated by a server which provides the storage service on the basis of user identifying information. More specifically, when the user acquires data from the storage service, the user inputs a user's name and a password to the IWB to transmit the user name and the password to the server.
At this time, as an input means for inputting the user identifying information, generally, a keypad displayed on the screen of the IWB is used. However, a large keypad is displayed in accordance with the size of the screen; therefore, there is a problem that the input user identifying information may be easily seen by others.
To cope with this, a small-sized screen or input means can be prepared in advance so as to prevent the act of inputting user identifying information from being seen by others. However, in this case, there is a problem that the reduction in size may cause a decrease in operability.
In view of the above, there is a need to enable a storage service to be securely used through a screen that many users can share.